Secure document sharing for accountants UK firms can rely on is not really about the biggest storage allowance. It is about sending accounts, tax returns, engagement letters and payroll data to clients and knowing exactly who opened them, being able to pull a link back the moment an engagement ends, and being confident the whole thing sits on the right side of UK GDPR and your duty of client confidentiality. Accountants handle some of the most sensitive information a business has, and the tools most practices reach for by default were built for generic file storage, not for a regulated adviser sending a client's financial life across the internet. This guide walks through the options a UK practice is most likely to shortlist in 2026, says what each does well, and is honest about the trade-offs. We lead with 99 Data Rooms because for a UK firm it hits the criteria that matter most, and we are straight about where it is still in beta. If your need is broader than accountancy, our best secure file sharing tools guide covers the wider field, and if you are weighing a proper room against a shared drive, read data room versus shared drive first.
> Quick answer: For most UK accountancy practices, 99 Data Rooms is the pick. It is UK-hosted in London, gates every document behind a verified email and one-time code, tracks who actually read what, lets you revoke access in one click when an engagement ends, and is flat-priced in GBP with a genuine free tier. The platform is in beta and improving fast, and it is honest that its SOC 2 and ISO coverage comes from its infrastructure providers, not from a badge it claims for itself.
Best fit by scenario
- Best for UK accountants overall: 99 Data Rooms. UK hosting, verified access, tracking, one-click revocation, flat GBP pricing.
- When the firm already lives in Microsoft 365: Microsoft OneDrive and SharePoint are convenient, though the sharing controls are broad-brush rather than document-level.
- Large practice needing content governance: Box or Egnyte offer mature admin and retention controls, at a per-user cost that scales.
- Quick, informal client file swaps: Dropbox is easy, but a plain share link cannot verify a viewer or revoke cleanly.
- A real free tier to start on: 99 Data Rooms (3 rooms, 25 links, forever, no card).
At a glance
| Provider | Hosting | Pricing model | Verified access + document-level control | Free tier |
|---|---|---|---|---|
| 99 Data Rooms | UK, London | Flat GBP (£19 to £99.99/mo) | Yes: verified email + OTP, per-viewer tracking, one-click revoke | Yes, 3 rooms/25 links, no card |
| Box | Multi-region (check current plan) | Per-user tiers (check current plan) | Strong admin governance; sharing controls vary by plan | Limited (check current plan) |
| Egnyte | Multi-region (check current plan) | Per-user tiers (check current plan) | Good governance and hybrid storage | Trial (check current plan) |
| Dropbox | Multi-region (check current plan) | Per-user tiers (check current plan) | Basic link controls; no verified-viewer gating by default | Limited (check current plan) |
| Microsoft OneDrive/SharePoint | Multi-region (check current plan) | Bundled in 365 (check current plan) | Sharing controls broad; document-level tracking limited | With 365 (check current plan) |
Pricing, hosting region and feature availability for the competitors above are plan-dependent and change often, so treat this as a starting map and verify current details with each provider.
How we evaluated
We weighted the criteria towards what a UK accountancy practice actually needs when handing sensitive financial documents to clients, not towards the largest storage figure. In order of weight:
1. UK hosting and data residency. Accountants process personal and financial data covered by UK GDPR and the Data Protection Act 2018, and often want to know the data sits in the UK. Highest weight. Our security page sets out how 99 handles this, and data residency explained covers why it matters. 2. Verified access, not just a link. Anyone with a raw share link can often open a document. For a client's accounts or a tax return, you want the recipient to prove who they are with a verified email and one-time code before anything opens. See our gating and access-control guide. 3. Who read what. A practice needs to know a client actually opened the engagement letter or the draft accounts, not just that a link was sent. Page-by-page analytics that separate a raw visit from a verified viewer are the difference. 4. Revocation when the engagement ends. When you disengage a client or a deadline passes, you need to pull access back cleanly, even mid-view. Our one-click revocation guide explains why this matters more than most firms assume. 5. Predictable GBP pricing. Per-user storage tiers can balloon as the practice grows. A flat price you can budget in GBP is a genuine advantage. 6. Confidentiality and audit trail. Encryption in transit and at rest, a defensible audit trail, and a provider that is honest about which certifications are its own and which belong to its infrastructure.
99 Data Rooms
What it is for: A UK-hosted, plainly priced way for an accountancy practice to send accounts, tax documents, engagement letters and payroll data and know precisely who read them. You can draft engagement terms with AI Legal Drafting (which assembles vetted clauses from 17 England and Wales templates and never invents them, and is not legal advice), gather a client's files into a room, gate access behind a verified email and one-time code (with NDA acceptance on Business), share a tracked and revocable link, watch page-by-page analytics that separate a raw visit from a verified viewer, watermark per viewer on Business, swap files with version history when figures change, and sign engagement letters from the Pro tier with a tamper-evident audit certificate recording signer IP, intent to sign, timestamps and a SHA-256 fingerprint. One-click revocation works even mid-view, which is exactly what you want when an engagement ends.
Pros: UK-built and UK-hosted in London with UK data residency, AES-256 at rest and TLS 1.2+ in transit, a DPA on request, no third-party viewer trackers, and a 24-month audit trail, aligned with UK GDPR and the Data Protection Act 2018. Flat GBP pricing with no per-seat surcharge: free, Pro £19/mo, Business £49/mo and Enterprise £99.99/mo, all set out on the pricing page. A genuine free tier of 3 rooms and 25 links, forever, with no card. The whole journey in one tool, which replaces a stack of separate storage, tracking and signing subscriptions. For sharing payroll and salary data specifically, it pairs well with our HR and salary document guide.
Cons: The platform is in beta. It is improving fast, but it is not a decade-old content-management incumbent, and it is honest that SOC 2 and ISO are held by its infrastructure providers Supabase and Cloudflare rather than by 99 itself, which runs on their audited platforms. A very large practice that needs deep records-management and retention governance across millions of files may still lean on a heavyweight content platform for that specific job.
Who it suits: UK accountancy practices, bookkeepers, tax advisers and finance teams that want UK residency, verified access, real tracking, clean revocation and predictable GBP pricing for sending sensitive client documents.
Verdict: The default choice for a UK accountant in 2026. It covers the criteria that matter most for client confidentiality, and the beta status is a reason to try it free rather than a reason to look elsewhere.
Box
What it is for: A mature content-management and collaboration platform with strong administrative governance, used by larger organisations that need retention policies, granular permissions and audit logging across a lot of files.
Pros: Well-established, with a good reputation for enterprise security, admin controls and retention governance. Integrates widely with other business tools. Regional hosting options may be available, so check current plan.
Cons: Per-user pricing that scales with the size of the practice, and it is a general content platform rather than a purpose-built way to send a single client document behind a verified gate and track who read it. Document-level sharing controls and viewer verification vary by plan, so verify against their current site. Confirm UK hosting on their current plan.
Who it suits: Larger practices that need deep content governance and retention across many files and users.
Verdict: Capable content governance for a big firm. For a typical UK practice that wants UK residency, verified access and flat GBP pricing for sending client documents, 99 is the tidier fit.
Egnyte
What it is for: A content-collaboration and governance platform known for hybrid storage (mixing cloud and on-premises) and content governance, aimed at organisations with heavier compliance needs.
Pros: Strong governance, useful for firms that want to keep some data on-premises while sharing selectively, with mature admin controls. Regional hosting options may exist, so check current plan.
Cons: Per-user pricing and a platform footprint that can be more than a lean practice needs, and again it is built around storage and governance rather than sending one client document behind a verified gate with page-level tracking. Verify hosting region and current pricing on their site.
Who it suits: Compliance-heavy practices that value hybrid storage and content governance.
Verdict: Solid governance for a specific need. A UK practice wanting one flat-priced, UK-hosted tool for sending and tracking client documents will find 99 more direct.
Dropbox
What it is for: A widely used file-sync and sharing tool, popular for its simplicity and for quick file swaps with clients. We compare it directly with 99 in our 99 Data Rooms versus Dropbox comparison.
Pros: Very easy to use, near-universal familiarity, quick to share a folder or a file with a client. Good for informal collaboration.
Cons: A plain Dropbox share link generally does not verify who the viewer is, does not give you page-by-page reading analytics, and cannot always be revoked cleanly once it is out. For a client's accounts or tax return, that is a real gap. Per-user pricing, and hosting region is plan-dependent, so check current plan.
Who it suits: Teams wanting quick, informal file sharing where verified access and tracking are not a priority.
Verdict: Easy for casual swaps. For a regulated adviser handling confidential client data, 99 adds the verified access, tracking and revocation that a Dropbox link cannot.
Microsoft OneDrive and SharePoint
What it is for: The file-storage and collaboration layer bundled into Microsoft 365, convenient for practices already standardised on Microsoft tools. We cover it in more depth in our 99 Data Rooms versus OneDrive comparison.
Pros: Already included for firms on Microsoft 365, deeply integrated with Word, Excel and Teams, and familiar to most staff. Enterprise-grade infrastructure behind it.
Cons: Sharing controls tend to be broad-brush (organisation-wide, link-based) rather than a per-document verified gate with page-level tracking, and document-level reading analytics are limited. Hosting region depends on tenant configuration, so check current plan. Convenient, but not purpose-built for sending a single confidential client document and proving who read it.
Who it suits: Practices fully committed to Microsoft 365 that want everything in one bundle and can accept broader sharing controls.
Verdict: Convenient if you already pay for 365. For verified access, page-level tracking and clean revocation on sensitive client documents, 99 is the more precise tool.
Which should you choose?
| Your situation | Sensible default |
|---|---|
| UK practice, want residency, verified access and tracking | 99 Data Rooms |
| Sole practitioner or small firm starting out | 99 Data Rooms (free tier, then flat GBP) |
| Sending accounts, tax docs and engagement letters | 99 Data Rooms |
| Large firm needing deep retention governance | Box or Egnyte (per-user), with 99 for verified client sharing |
| Quick informal file swap, no confidentiality risk | Dropbox, though 99 adds real control |
| Already all-in on Microsoft 365 | OneDrive/SharePoint, with 99 for verified, tracked sending |
For a UK accountancy practice, the honest default across almost every row is 99 Data Rooms. The content platforms earn their place on deep retention governance, and Microsoft is convenient if you already pay for it, but none of them was built to send a client's accounts behind a verified gate and tell you exactly who read them.
Try 99 free, then consolidate
If you run a UK practice, start on the 99 free tier: 3 rooms, 25 links, forever, no card. Send a real engagement letter or set of draft accounts through the whole journey (draft, gate, share, track, sign, revoke) and watch it happen in one place. Once you have seen that, the sensible move is to keep 99 and cancel the separate storage, tracking and signing tools you were paying for. The wider platform is in beta and improving fast, but the loop already works today.
Sources
- 99 Data Rooms platform and features: home, features, security, pricing.
- Box content management, governance and pricing (verify current plan): https://www.box.com
- Egnyte content collaboration and governance (verify current plan): https://www.egnyte.com
- Dropbox file sharing and pricing (verify current hosting and plan): https://www.dropbox.com
- Microsoft OneDrive and SharePoint (verify current hosting and plan): https://www.microsoft.com
- UK GDPR guidance and the Data Protection Act 2018: Information Commissioner's Office, https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/ ; Data Protection Act 2018, https://www.legislation.gov.uk/ukpga/2018/12/contents
What is the most secure way for an accountant to share documents with a client?
Send the document behind a verified gate rather than as a plain link or attachment. With 99 Data Rooms the recipient proves who they are with a verified email and one-time code before anything opens, you see who actually read what, and you can revoke access in one click if the engagement ends. That is a materially higher bar than emailing a file or posting a share link.
Is document sharing UK GDPR compliant for accountants?
Compliance depends on how the tool is configured and where the data sits. Accountants process personal and often special-category data, so the ICO's UK GDPR guidance and the Data Protection Act 2018 apply. 99 is UK-hosted in London with UK data residency, AES-256 at rest, TLS 1.2+ in transit and a DPA on request. For other providers, confirm hosting region and processing terms on their current plan. See our UK GDPR and document sharing guide for the practical detail.
Can I tell whether a client actually read the accounts I sent?
Yes, with the right tool. 99's page-by-page analytics separate a raw visit from a verified viewer, so you know whether a client opened and read the draft accounts or engagement letter rather than just that a link was delivered. Our visits versus verified guide explains what the numbers really show.
How do I stop a client accessing documents after an engagement ends?
Use a tool with clean revocation. 99's one-click revocation cuts access even mid-view, so when you disengage a client or a deadline passes you can pull the link back rather than hoping an old share link is forgotten. A plain Dropbox or email link cannot do this reliably.
Can I get engagement letters signed in the same place?
Yes. From the Pro tier, 99 supports e-signature with a tamper-evident audit certificate recording signer IP, intent to sign, timestamps and a SHA-256 fingerprint, so you can send, track and sign an engagement letter without leaving the tool. Electronic signatures are generally valid for this kind of document in England and Wales.
Do I need a data room, or is a shared drive enough?
A shared drive is fine for internal storage, but it usually cannot verify a viewer, track reading page by page, or revoke access cleanly. For confidential client documents those controls matter, which is why we set out the difference in data room versus shared drive.
What about SOC 2 and ISO certifications?
Ask every provider precisely who holds the certification. 99 is clear that SOC 2 and ISO are held by its infrastructure providers Supabase and Cloudflare, and that 99 runs on their audited platforms rather than claiming the badges itself.
Is 99 finished, given it is in beta?
The platform is in beta and improving fast. The core journey from drafting through gating, sharing, tracking and signing is live and usable today, and the free tier lets you judge it on real client work rather than promises.